The subject invention is directed generally to hologram structures, and more particularly to an encoded hologram for laminated identification cards and the like which contains human viewable information as well as machine readable indicia that is substantially incapable of being resolved by human vision.
Laminated identification cards such as those containing a photograph of the authorized card holder are widely used for security purposes. Laminated identification cards commonly include other human readable information as well as machine readable information contained on a magnetic strip for example.
An important consideration with laminated identification cards is counterfeiting and/or tampering. One approach to preventing counterfeiting and/or tampering is to incorporate human or machine readable holograms that are difficult to remove into laminated identification cards so that tampering would result in damage to the hologram which would be rendered unreadable. Counterfeiting is prevented by utilizing a hologram whose construction is difficult to ascertain, whose presence is difficult to ascertain, or which is difficult to copy. However, the provision of both human readable and machine readable holograms in accordance with known techniques requires two or more holograms.